Kentucky Section AIPG

2005 Spring Field Trip and Awards BanquetHilton-Cincinnati Airport

Florence, KentuckyApril 23, 2005

GEOLOGY OF NORTHERN KENTUCKY AND

THE OHIO RIVER VALLEYWilliam “Drew “ Andrews-Geologist

Kentucky Geological Survey

Rick Bullard, InstructorDepartment of Physics and Geology

Northern Kentucky University

John Rockaway, ProfessorDepartment of Physics and Geology

Northern Kentucky University

The Kentucky Section AIPG would like to thank the following sponsors for their contribution.

Contractors to the Petroleum Industry

Quaternary Geology in Boone County, Northern Kentucky Compiled by William Andrews, Jr.

Kentucky Geological Survey Many people have assisted with data collection included in this brief guide. Special thanks are due to John Barker (Big Bone Lick State Park), Sarah Johnson (NKU), Steven L. Martin and Michael Murphy (KGS), Dr. Harry Rowe (UK), and Dr. Barry Maynard (UC). Bedrock Geology Upper Ordovician limestone and shale dominate the bedrock geology of the field trip area (Swadley, 1969, 1971a). In Kentucky, this sequence is divided into mapping units primarily on the basis of limestone vs. shale content (Table 1.). This thick package of shaly bedrock is relatively easily eroded compared to sequences dominated by only sandstone or limestone. Combined with the proximity of the major drainage in the Ohio River, this has led to significant incision of the area and the development of fairly rugged hills and steep-sided valleys. Upon closer inspection, however, the landscape has a more complex history than simply streams eroding their valleys down through time. Excellent overviews of the field trip area geology can be found in Ray (1974) and Potter (1996).

Age Unit % Limestone Thickness Upper Ordovician Bull Fork Formation ~50% >100 ft. Upper Ordovician Bellevue Tongue of Grant Lake Limestone >90% 5 – 40 ft. Upper Ordovician Fairview Formation ~50% 90 – 120 ft. Upper Ordovician Kope Formation 10-20% 200 – 230 ft. Middle Ordovician Point Pleasant Formation ~50% >20 ft.

Table 1. Summary of Ordovician bedrock units in the field trip area. Not-directly-represented-and-thus-speculative Mesozoic to Mid-Tertiary History The field trip area sits astride the Cincinnati Arch, a broad regional anticline separating the Appalachian Basin on the east from the Illinois Basin on the west. Based on regional stratigraphic patterns, sediments were probably deposited across this area throughout much of the Paleozoic, similar to the rocks preserved in the adjacent basins. No Triassic or Jurassic rocks have been identified in the region or adjoining basin areas. Cretaceous through mid-Tertiary coastal plain and shallow marine sediments are preserved in the Jackson Purchase of far western Kentucky (Olive, 1980). On the basis of fission track and conodont thermal maturity data (Harris and others, 1978; Roden and others, 1993), erosion of a Late Paleozoic depositional surface was apparently slow until the mid-Tertiary, and accelerated in the Miocene (Hulver, 1997). An estimated 400 to 800 m of overburden has been eroded from the crest of the Cincinnati Arch since the Mesozoic (Andrews, 2004). Teays River (Plio-Pleistocene) During the Pliocene and Early Pleistocene, meandering rivers drained central Kentucky and the highlands to the east. The Old Licking River and the Old Kentucky River flowed northward past Cincinnati to join the ancient Teays River system in central Ohio, before flowing west across central Indiana and Illinois, and turning south to follow the approximate modern path of the Mississippi River to the Gulf (Figure 1). The Old Ohio River was a much smaller stream than the modern Ohio, with its headwaters only reaching as far as Madison, Indiana. The Old Ohio River was comparable in size to the modern Salt River in central Kentucky. Remnants of these ancient river systems are apparent in abandoned high-level valleys and fluvial deposits found scattered in the uplands near master streams through central Kentucky and the field trip area (Figure 2). For the most recent review of the Teays River system and its tributaries, see Melhorn and Kempton (1991) and the articles therein. Granger and Smith (1998) and Granger (personal communication) has used cosmogenic Be10 dating to estimate the age of Teays River sediment at 1.1 to 1.45 My. Pleistocene Geologic History Pre-Illinoisan Ray (1974) provides a comprehensive yet outdated review of Quaternary geology in the field trip area. Early workers identified four major Pleistocene glaciations in the eastern United States: the Nebraskan (oldest), Kansan, Illinoisan, and Wisconsinan (youngest). These terms were used widely in the regional literature, until subsequent

work with tephra layers in the type areas of the Kansan and Nebraskan showed major complications in correlation and chronology. Numerous glaciations (over a dozen) have now been recognized in the Pleistocene of the central United States, with only the Illinoisan and Wisconsinan having reasonable chronologic or stratigraphic control; thus, the terms Kansan and Nebraskan are no longer appropriate. The USGS-KGS geologic mapping program (1960-1978) identified only one pre-Illinoisan glacial deposit in the area (Swadley, 1971b). Leighton and Ray (1965) identified two pre-Illinoisan glacial deposits in northern Kentucky in the Ohio Valley, and assigned these to the Nebraskan and Kansan. The two tills are difficult to distinguish, however, and these were considered one multi-phase glacial event by Teller (1970). Pre-Illinoisan glacial drift has been mapped along many of the ridgetops in the study area, and rests on top of the fluvial deposits of the Old Kentucky River (Swadley, 1971b). The pre-Illinoisan glaciations impounded the Teays River and its tributaries, disrupting the regional Teays River drainage pattern and assisting in the integration of the modern Ohio River. The sudden increase of drainage area for the lower Ohio River valley, and the dramatic decrease in distance to the Gulf of Mexico for the headwater streams of the Teays River system resulted in rapid incision and down-cutting by master streams and their tributaries in Kentucky. The literature on the evolution of the Ohio River is extensive; readers are encouraged to examine Ray (1974), Potter (1996), and Melhorn and Kempton (1991) for related articles. Deep Stage After the pre-Illinoisan glaciations, an extended interglacial period allowed the newly arranged Ohio River system to adjust to its new course and longitudinal profile. The change in stream profile during destruction of the Teays left the Ohio River and tributaries in disequilibrium, and a period of rapid downcutting ensued. The deepest erosion of the Ohio River bedrock valley occurred during this “Deep Stage” interglacial. Nearby tributaries also deeply incised to keep pace with the master stream level in the Ohio River valley. Illinoisan The Illinoisan glaciation reached into northern Kentucky, but the steep “Deep Stage” topography supposedly kept the glacial ice restricted to the valley bottoms, so Illinoisan till and outwash deposits are only identified along the margins of major stream valleys, and not on the adjacent ridgetops. The Illinoisan and pre-Illinoisan deposits are be distinguished by their topographic position (Figure 2), as well as by the intensity of weathering and alteration of the sediments and matrix materials (see Potter, 1996). The Illinoisan till and outwash partially filled the Ohio River valley, and dammed up adjacent tributaries, creating valley-bound lakes in many of the tributary valleys. After retreat of the Illinoisan ice, the Ohio River began to downcut into the Illinoisan valley deposits. Wisconsinan The Wisconsinan glaciers did not reach into northern Kentucky, but they dumped huge quantities of sand, gravel and silt into the Ohio River valley, filling the post-Illinoisan valley (Figure 2), and forming an extensive outwash valley train. The Wisconsinan outwash is distinguishable from the Illinoisan outwash only by topographic position along valley margins. The subsurface sand and gravel deposits are virtually indistinguishable from each other. As the outwash valley trains moved down valley, winds blowing off the cold glaciers picked up the siltier material, depositing it southward as loess blankets across much of northern and central Kentucky. Particles of fine sand coalesced into dunes near valley walls. Again, the outwash deposits dammed up tributary streams and led to extensive valley lakes in tributary valleys, such as that seen at Stop 1, Big Bone Lick State Park. Holocene Since the retreat of the Wisconsinan glaciers, the Ohio River and tributary streams have reworked and redeposited sandier and siltier materials in the modern floodplain. This floodplain sits lower than the surface of the Wisconsinan outwash, which remains as a terrace through the area. The sand and gravel of the outwash terraces along the Ohio River is produced for road aggregate and other uses. The relatively high outwash terrace has been an attractive place for settlement and occupation for the last 12,000 years or so. Figure 2 is a generalized profile showing the relationship of bedrock and Quaternary units in Boone County. The relative positions of our two morning stops, Big Bone Lick State Park and Boone Cliffs State Nature Preserve, are shown on the profile.

Old Ohio River

Teays River

Teays River

Teays River

Old Ky River

C

MOld Licking River

Figure 1. Map of Teays-age paleodrainage of the region, showing the field trip area (star). The Old Ohio River has its headwaters at the Madison divide (M), while the Old Kentucky and Old Licking drained northward to the Teays. Light gray lines show the limit of Wisconsin (thin) and pre-Wisconsin glaciations (thicker).

Old Ohio River

Teays River

Teays River

Teays River

Old Ky River

C

MOld Licking River

Figure 1. Map of Teays-age paleodrainage of the region, showing the field trip area (star). The Old Ohio River has its headwaters at the Madison divide (M), while the Old Kentucky and Old Licking drained northward to the Teays. Light gray lines show the limit of Wisconsin (thin) and pre-Wisconsin glaciations (thicker).

West

East

Ob

Ogb

Of

Ok - Kope Fm.

Op

Ob - Bull Fk. Fm.Ogb - Bellvue Tongue

Of

Ok

Op - Point Pleasant Fm.

Ob

Ogb

Of - Fairview Fm.

OkQid

QalQwo

QalQwla

QTf

Qo/Qd

OhioRiver

Big BoneCreek

Teays-age Old Kentucky

River(abandoned)

Boone Cliffs

Big Bone Lick

Unconsolidated DepositsQal Recent alluviumQwla Wisconsinan lacustrine depositsQwo Wisconsinan outwashQid Illinoisan drift (till? outwash?)Qo/Qd pre-Illinoisan drift (till? outwash?)QTf high-level fluvial deposits

Figure 2. Schematic cross section showing the bedrock stratigraphy and unconsolidated deposits in the field-trip area. Bedrock units are Upper Ordovician. Total relief in the area is approximately 500 feet. Adapted by Wm. Andrews from Swadley (1971a) Geologic Map of Part of the Rising Sun Quadrangle, USGS GQ-929.

“Deep stage” bedrock valley

West

Ob

Ogb

Of

Ok - Kope Fm.

Op

Ob - Bull Fk. Fm.Ogb - Bellvue Tongue

Of

Ok

Op - Point Pleasant Fm.

Ob

Ogb

Of - Fairview Fm.

OkQid

QalQwo

QalQwla

QTf

Qo/Qd

OhioRiver

Big BoneCreek

Teays-age Old Kentucky

River(abandoned)

Boone Cliffs

Big Bone Lick

East

Unconsolidated DepositsQal Recent alluviumQwla Wisconsinan lacustrine depositsQwo Wisconsinan outwashQid Illinoisan drift (till? outwash?)Qo/Qd pre-Illinoisan drift (till? outwash?)QTf high-level fluvial deposits

Figure 2. Schematic cross section showing the bedrock stratigraphy and unconsolidated deposits in the field-trip area. Bedrock units are Upper Ordovician. Total relief in the area is approximately 500 feet. Adapted by Wm. Andrews from Swadley (1971a) Geologic Map of Part of the Rising Sun Quadrangle, USGS GQ-929.

“Deep stage” bedrock valley

STOP 1. Big Bone Lick State Park NOTE: Stop 1 is a Kentucky State Park attracting numerous tourists and local/regional campers every year. Collecting of artifacts, etc., is prohibited in the park without prior permission of the Park Naturalist. A cooperative study by the Kentucky Geological Survey, Northern Kentucky University, University of Kentucky, and the University of Cincinnati, supported by the U.S. Geological Survey, has been investigating the geology, geomorphology, geochemistry, and hydrology of Big Bone Lick State Park. A series of five cores and one auger hole were collected in July 2004 and examined by students and faculty at these institutions to provide background data for the geological interpretation of the park for visitor education and for site management. A groundwater monitoring well was installed in one of the core holes. Stop 1 will be in the area near the monitoring well, Big Bone Creek, and two of the active saline springs. The floodplain of Big Bone Creek is inset into Wisconsinan lacustrine terrace deposits developed due to aggradation of Ohio River outwash episodically impounding Big Bone Creek. The lacustrine material is primarily comprised of bluish gray clayey silt and silty clay, which is locally laminated and contains sparse sandier layers. University of Nebraska paleontological excavations found preserved bones of Pleistocene mammoth, mastodon, giant ground sloth, bison, musk ox, caribou and horses on and in the lacustrine deposits (Schultz and others, 1967). The floodplain of Big Bone Creek overlies the lacustrine material and includes brown silty clay loam and silt loam up to 12 feet thick. University of Nebraska paleontological studies found historic artifacts and bones of historic domesticated and Holocene wild animals in the brown floodplain deposits (Schultz and others, 1967). The contact between the brown floodplain deposits and the underlying “blue clay” of the lacustrine deposit can be seen in the bank of Big Bone Creek at Stop 1. The 2004 drilling determined bedrock at this location to be approximately 21 feet below ground surface. The critical geological feature of Big Bone Lick State Park is a series of saline springs flowing from the floodplain of Big Bone Creek. These springs attracted large Pleistocene and Holocene vertebrates who needed the salt as part of their diet. As the animals crossed the swampy lake flat to access the salt, many became mired in the mud and were trampled or drowned. The presence of the animals in turn attracted prehistoric peoples who hunted the animals and collected salt for their own use. Early settlers manufactured salt from the Big Bone Lick springs. In the 19th century, the springs became a medicinal resort, attracting numerous travelers to consume the saline waters for their perceived health benefits. Jillson (1936) discusses the geology, paleontology and history of Big Bone Lick. According to recent analyses overseen by Dr Barry Maynard at the University of Cincinnati, the major-element chemistry of the groundwater from these springs is dominated by sodium chloride. Surface water samples from Big Bone Creek are calcium-carbonate rich. In a comparison with regional brine analyses, Dr. Maynard suggests these springs are tapping a source chemically similar to brines found in the Illinois Basin to the west. Although they will not be viewed at this stop, Plio-Pleistocene fluvial deposits of the Old Kentucky River cap the upland where the modern Big Bone Lick campground is located. The fluvial deposits are identified mainly by the presence of pebbles of well rounded quartz, subangular brown chert, and geodes. These lithologies are derived form bedrock outcrops in east-central and south-central Kentucky and were carried to this location by a north-flowing segment of the Old Kentucky River flowing toward the Teays River system to the north. The bedrock at the park is shale and limestone of the Upper Ordovician Kope Formation.

Diorama of foundering Pleistocene mammals at the park.

The July 2004 cooperative drilling project extracted five soft-sediment cores at Big Bone Lick State Park, and involved cooperation from the U.S. Geological Survey, Kentucky Geological Survey, University of Kentucky, Northern Kentucky University, and the University of Cincinnati.

View looking down from bank of Big Bone Creek at Stop 1, showing contact (dashed line) between lacustrine (left/below) and floodplain (right/above) sediments.

STOP 2. Boone Cliffs State Nature Preserve NOTE: Stop 2 is a state nature preserve protecting unique and fragile natural habitats. Please stay on the trail. Collecting or disturbing plants, animals (and yes, rocks) is prohibited. At the last pre-field trip visit (April 14 2005) several native woodland plants were blooming, including common blue violet (purple), blue phlox (purple), dwarf larkspur (dark purple), sessile trillium (maroon), Dutchman’s-breetches (white), ragwort (yellow), and others. Even without rock hammers, there will be plenty to see and enjoy. Boone Cliffs is a 75-acre tract of old growth forest including distinctive cliffs of consolidated Early(?) Pleistocene glacial-outwash congolomerate overlying shale and limestone of the Kope through Bull Fork Formations. The conglomerate includes pebbles and cobbles of limestone, quartz and quartzite, sandstone and siltstone, chert, igneous/metamorphic rocks and geodes. Most pebbles are less than 4 inches (10 cm) in diameter, but some slabs of limestone range up to 18 inches (45 cm), as we will see at this stop. Crossbed orientation directions in the conglomerate range from northeast (30°) to southeast (145°) with dips as high as 20°. Overall, these outwash deposits have a southbound trend and overlie northbound fluvial sediment of the Old Kentucky River, which flowed into the Teays Valley System north of Cincinnati. Although no direct geochronologic measurements have been made, they are presumed to be pre-Illinoisan and thus would represent the glacial advance that disrupted the Plio-Pleistocene Teays River and encouraged the integration of the modern Ohio River system. Cosmogenic Be10 dating on northbound Old Kentucky River sediment near Carrollton suggests an age of 1.1 to 1.45 My for the Teays-age sediment (Granger and Smith, 1998; Granger, personal communication).

Crossbedded conglomerate exposed at Boone Cliffs; filled rectangle is roughly 1 inch in length.

Photograph of limestone slabs in conglomerate at Boone Cliffs

REFERENCES (Stops 1 and 2 and supporting discussion) Andrews, W.M., 2004, Geological controls on Plio-Pleistocene drainage evolution of the Kentucky River in central

Kentucky: University of Kentucky, PhD dissertation, 222 p. Granger, D.E., and Smith, A.L., 1998, Early Laurentide glaciation and creation of Ohio River dated by radioactive

decay of cosmogenic Al26 and Be10 in proglacial sediments (abstract): Geological Society of America Abstracts with Programs, v. 30, n. 7, p. 298.

Harris, A.G., Harris, L.D., and Epstein, J.B., 1978, Oil and gas data from Paleozoic rocks in the Appalachian Basin; maps for assessing hydrocarbon potential and thermal maturity (conodont color alteration isograds and overburden isopachs): U.S. Geological Survey Miscellaneous Investigations Series MI-917, 4 sheets.

Hulver, M.L., 1997, Post-orogenic evolution of the Appalachian mountain system and its foreland: Chicago, University of Chicago, Ph.D. dissertation, 1055 p.

Jillson, W. R, 1936, Big Bone Lick—an outline of its history, geology and paleontology: Standard Printing Company, Louisville, Kentucky (Big Bone Lick Association Publication No. 1), 164 p.

Leighton, M.M., and Ray, L.L., 1965, Glacial deposits of Nebraskan and Kansan age in northern Kentucky, Geological Survey Research 1965.: U.S. Geological Survey Professional Paper PP-525B, p. B126-B131.

Melhorn, W.N., and Kempton, J.P., 1991, Geology and hydrogeology of the Teays-Mahomet bedrock valley systems: Geological Society of America Special Paper No. 258, 128 p.

Olive, W.W., 1980, Geologic maps of the Jackson Purchase region, Kentucky: U.S. Geological Survey Miscellaneous Investigations Series I-1217, 11 p.

Potter , P.E., 1996, Exploring the geology of the Cincinnati/northern Kentucky region: Kentucky Geological Survey Special Publication No. SP-22, 118 p.

Ray, L.L., 1974, Geomorphology and Quaternary geology of the glaciated Ohio River valley; a reconnaissance study: U.S. Geological Survey Professional Paper PP-826, 77 p.

Roden, M.K., Elliott, W.C., Aronson, J.L., and Miller, D.S., 1993, A comparison of fission-track ages of apatite and zircon to the K/Ar ages of illite-smectite (I/S) from Ordovician K-bentonites, southern Appalachian Basin: Journal of Geology, v. 101, no. 5, p. 633-641.

Schultz, C.B., Tanner, L.G., Whitmore, F.C., Ray, L.L., and Crawford, E.C., 1967, Big Bone Lick Kentucky—a pictorial history of the paleontological excavations at this famous fossil locality from 1962 to 1966: University of Nebraska Museum Notes, n. 33, 12 p.

Swadley, W.C., 1969, Geologic map of the Union quadrangle, Boone County, Kentucky: U.S. Geological Survey Geologic Quadrangle Map No. GQ-779, scale 1:24,000, 1 sheet.

Swadley, W.C., 1971a, Geologic map of the Rising Sun quadrangle, Boone County, Kentucky: U.S. Geological Survey Geologic Quadrangle Map No. GQ-929, scale 1:24,000, 1 sheet.

Swadley, W.C., 1971b, The preglacial Kentucky River of northern Kentucky: U.S. Geological Survey Professional Paper PP-750D, p. D127-D131.

Teller, J.T., 1970, Early Pleistocene glaciation and drainage of southwest Ohio, southeast Indiana and northern Kentucky: Cincinnati, University of Cincinnati, Ph.D. dissertation, 115 p.

View of the Ohio River valley from KY 18, south of McVille, looking north.